1. Technical Field
The present invention relates generally to the field of data processing systems and more specifically to a method, system, and computer program product for managing persistent data across different releases.
2. Description of Related Art
A hardware management console (HMC) is a tool that is designed to help manage a data processing system, and in particular the central electronics complex (CEC). The management functions of the HMC include simple tasks such as powering the CEC on and off. The HMC also performs more complicated tasks that involve creating logical partitions (LPARs) in the CEC, and configuring profiles used in the activation of those LPARs to indicate which hardware resources will be used by the running partition.
The information used by the HMC to define these partitions and profiles is saved in a dedicated persistent area in non-volatile random access memory (NVRAM) to prevent its loss, to avoid having the user reenter this information every time the HMC is started, and to enable the sharing of this information with other HMCs that may be connected and managing the same CEC. This information used to define these partitions and profiles is saved to a dedicated persistent area in NVRAM, referred to herein as the save area. The save area is formatted in a specific way according to the current release version of the CEC firmware. Each time the release version of the CEC changes, the formatting of the save area may change.
A problem arises when an HMC that has firmware running at a particular release version tries to manage a CEC running at a more recent version. For example, a new version of firmware may be installed on the CEC, but the corresponding HMC firmware release version may not be installed on the HMC. The format of the save area in NVRAM can and does change from one release version of the CEC to another. Changes may be required because of new properties being added to partition profiles which are stored in the save area. The size of the save area may need to change to accommodate an increase in the capability of a new release of the CEC.
For example, an early version of the CEC might support only 16 partitions while a later version of the CEC may support 32. The size of the save area for the later version would have to increase to accommodate this change in the amount of information that needs to be saved. Simply increasing the size of the save area to allow for future growth would not help this situation because any modifications to the partition or profile information would make a change necessary in the format of the save area. This change would not be understood by the older version of the HMC and would make the HMC's parsing of the save area data incorrect.
Currently, since an earlier version of the HMC cannot tell what may have changed in a newer version of the save area, the older version HMC will be unable to manage the CEC. There is no forward compatibility. At this point, the only option open to the HMC administrator is to upgrade the release version of the HMC.
Therefore, a need exists for a method, system, and product for managing persistent data across multiple different releases so that an HMC using an older version release will be able to manage a CEC using an updated version.